Comorbidity in dementia: an autopsy study.

CONTEXT: There is a paucity of accurate postmortem data pertinent to comorbid medical conditions in patients with dementia, including Alzheimer disease. OBJECTIVES: The purposes of this study were (a) to examine general autopsy findings in patients with a dementia syndrome and (b) to establish patterns of central nervous system comorbidity in these patients. DESIGN: Review of autopsy reports and selected case material from 202 demented patients who had "brain-only" autopsies during a 17-year period (1984-2000) and from 52 demented patients who had general autopsies during a 6-year period (1995-2000). SETTING: Large academic medical center performing approximately 200 autopsies per year. RESULTS: Among the 52 patients who underwent complete autopsy, the most common cause of death was bronchopneumonia, which was found in 24 cases (46.1%). Other respiratory problems included emphysema, found in 19 (36.5%) of 52 patients, and pulmonary thromboembolism, found in 9 (17.3%) of 52 patients. In 6 cases, pulmonary thromboembolism was the proximate cause of death. Twenty-one (40.3%) of the 52 patients had evidence of a myocardial infarct (varying ages) and 38 (73.1%) had atherosclerotic cardiovascular disease, 27 of a moderate to severe degree. Four clinically unsuspected malignancies were found: 1 each of glioblastoma multiforme, diffusely infiltrative central nervous system lymphoma, pancreatic adenocarcinoma, and adenocarcinoma of the lung. One patient with frontotemporal dementia and amyotrophic lateral sclerosis died of severe meningoencephalitis/ventriculitis, probably secondary to seeding of the central nervous system by an infected cardiac valve. Of the 202 demented patients who underwent brain-only autopsies, the following types of dementia were found: 129 (63.8%) cases showed changes of severe Alzheimer disease, 21 (10.4%) showed combined neuropathologic abnormalities (Alzheimer disease plus another type of lesion, such as significant ischemic infarcts or diffuse Lewy body disease), 12 (5.9%) cases of relatively pure ischemic vascular dementia, 13 (6.4%) cases of diffuse Lewy body disease, and 8 (4.0%) cases of frontotemporal dementia. The remaining 19 (9.4%) patients showed miscellaneous neuropathologic diagnoses, including normal pressure hydrocephalus and progressive supranuclear palsy. Among the demented patients, 92 (45.5%) had cerebral atherosclerosis, which was moderate to severe in 65 patients (32.2%). CONCLUSIONS: Some of the conditions found at autopsy, had they been known antemortem, would likely have affected clinical management of the patients. Autopsy findings may be used as a quality-of-care measure in patients who have been hospitalized in chronic care facilities for a neurodegenerative disorder.